miR-145通过调节细胞周期相关蛋白表达水平抑制乳腺癌MCF-7细胞增殖的机制研究

The mechanism of miR-145 inhibiting the proliferation of breast cancer MCF-7 cells by regulating the expression level of cell cycle associated proteins

目的:探索微小RNA(miR-145)对乳腺癌人巨噬细胞趋化因子(MCF-7)细胞增殖的抑制作用及miR-145抑制乳腺癌细胞增殖的具体分子机制。方法:定量聚合酶链反应实验检测miR-145在转染试剂RNAi MAX中的转染效率。细胞计数试剂盒(CCK)-8实验检测miR-145过表达后,乳腺癌人巨噬细胞趋化因子(MCF)-7细胞的增殖曲线。流式细胞术检测过表达miR-145对乳腺癌MCF-7细胞周期分布的影响。蛋白质印记法检测过表达miR-145对乳腺癌MCF-7细胞周期相关蛋白P21、细胞周期蛋白cyclin D1表达的调控作用。结果:RNAi MAX能够有效转染miR-145进入乳腺癌MCF-7细胞内,且转染组miR-145表达量显著高于对照组细胞(P<0.05)。CCK-8实验结果表明过表达miR-145能够显著抑制乳腺癌MCF-7细胞的增殖(P<0.05)。流式细胞实验结果表明过表达miR-145能够显著提高乳腺癌MCF-7细胞在G0/G1期的比例。蛋白质印记法检测结果显示过表达miR-145能够降低周期相关蛋白P21、cyclin D1的表达水平。结论:研究结果表明miR-145能够抑制乳腺癌MCF-7细胞的增殖,这种抑制与细胞周期相关蛋白P21、cyclin D1的表达水平降低相关,该结果使细胞周期停滞于G0/G1期,进而抑制肿瘤发展。

Objective:To investigate the inhibiting effect of microRNA(miR)-145 on the proliferation of macrophage chemotactic factor 7(MCF-7)cells in breast cancer,and to test the molecular mechanism of miR-145 inhibiting the proliferation of cancer cells.Methods:The transfection of miR-145 by RNAi MAX was detected by quantitative polymerase chain reaction.The proliferation result of breast cancer MCF-7 cells was detected by cell countingkit-8(CCK-8)assay after overexpression of miR-145.The effect of overexpression of miR-145 on the cell cycle distribution of MCF-7 cells was examined by flow cytometry.The regulation of overexpression of miR-145 on the expression of cell cycle-associated proteins P21 and Cyclin D1 in breast cancer MCF-7 cells were detected by western blot.Results:RNAi MAX was able to efficiently transfect miR-145 into MCF-7 cancer cells.The expression of miR-145 in the transfected group was significantly higher than control group(P<0.05).CCK-8 results indicated that overexpression of miR-145 significantly inhibited the proliferation of MCF-7 cells(P<0.05).Flow cytometry results showed that overexpression of miR-145 significantly increased the proportion of G0/G1 phase in MCF-7 cells.Western blot results indicated that overexpression of miR-145 reduced the expression levels of the cycle-associated proteins P21 and Cyclin D1.Conclusion:The results indicate that miR-145 inhibits the proliferation of MCF-7 cells,and miR-145 arrest the cancer cells at G0/G1 stage in cell cycle by attenuating the expression levels of the cycle-associated proteins P21 and cyclin D1.